iommu/amd: Tidy up DMA ops init

Now that DMA ops are part of the core API via iommu-dma, fold the
vestigial remains of the IOMMU_DMA_OPS init state into the IOMMU API
phase, and clean up a few other leftovers. This should also close the
race window wherein bus_set_iommu() effectively makes the DMA ops state
visible before its nominal initialisation - it seems this was previously
fairly benign, but since commit a250c23f15 ("iommu: remove
DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE") it can now lead to the strict flush
queue policy inadvertently being picked for default domains allocated
during that window, with a corresponding unexpected perfomance impact.

Reported-by: Jussi Maki <joamaki@gmail.com>
Tested-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Fixes: a250c23f15 ("iommu: remove DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE")
Link: https://lore.kernel.org/r/665db61e23ff8d54ac5eb391bef520b3a803fcb9.1622727974.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Robin Murphy 2021-06-03 14:48:21 +01:00 committed by Joerg Roedel
parent 8124c8a6b3
commit be227f8e99
3 changed files with 13 additions and 25 deletions

View file

@ -11,8 +11,6 @@
#include "amd_iommu_types.h"
extern int amd_iommu_init_dma_ops(void);
extern int amd_iommu_init_passthrough(void);
extern irqreturn_t amd_iommu_int_thread(int irq, void *data);
extern irqreturn_t amd_iommu_int_handler(int irq, void *data);
extern void amd_iommu_apply_erratum_63(u16 devid);

View file

@ -231,7 +231,6 @@ enum iommu_init_state {
IOMMU_ENABLED,
IOMMU_PCI_INIT,
IOMMU_INTERRUPTS_EN,
IOMMU_DMA_OPS,
IOMMU_INITIALIZED,
IOMMU_NOT_FOUND,
IOMMU_INIT_ERROR,
@ -2895,10 +2894,6 @@ static int __init state_next(void)
init_state = ret ? IOMMU_INIT_ERROR : IOMMU_INTERRUPTS_EN;
break;
case IOMMU_INTERRUPTS_EN:
ret = amd_iommu_init_dma_ops();
init_state = ret ? IOMMU_INIT_ERROR : IOMMU_DMA_OPS;
break;
case IOMMU_DMA_OPS:
init_state = IOMMU_INITIALIZED;
break;
case IOMMU_INITIALIZED:

View file

@ -30,7 +30,6 @@
#include <linux/msi.h>
#include <linux/irqdomain.h>
#include <linux/percpu.h>
#include <linux/iova.h>
#include <linux/io-pgtable.h>
#include <asm/irq_remapping.h>
#include <asm/io_apic.h>
@ -1773,13 +1772,22 @@ void amd_iommu_domain_update(struct protection_domain *domain)
amd_iommu_domain_flush_complete(domain);
}
static void __init amd_iommu_init_dma_ops(void)
{
swiotlb = (iommu_default_passthrough() || sme_me_mask) ? 1 : 0;
if (amd_iommu_unmap_flush)
pr_info("IO/TLB flush on unmap enabled\n");
else
pr_info("Lazy IO/TLB flushing enabled\n");
iommu_set_dma_strict(amd_iommu_unmap_flush);
}
int __init amd_iommu_init_api(void)
{
int ret, err = 0;
int err = 0;
ret = iova_cache_get();
if (ret)
return ret;
amd_iommu_init_dma_ops();
err = bus_set_iommu(&pci_bus_type, &amd_iommu_ops);
if (err)
@ -1796,19 +1804,6 @@ int __init amd_iommu_init_api(void)
return 0;
}
int __init amd_iommu_init_dma_ops(void)
{
swiotlb = (iommu_default_passthrough() || sme_me_mask) ? 1 : 0;
if (amd_iommu_unmap_flush)
pr_info("IO/TLB flush on unmap enabled\n");
else
pr_info("Lazy IO/TLB flushing enabled\n");
iommu_set_dma_strict(amd_iommu_unmap_flush);
return 0;
}
/*****************************************************************************
*
* The following functions belong to the exported interface of AMD IOMMU